egames, if the accumulator is already a year old, then in any case it will not roll the robot for 2 hours.
I had 2 pandas, there were enough batteries out of the box for just a year. After a year, they worked only 20-25 minutes.
I suspect that already a tired battery can go with Ali, which exacerbates the situation.
Charge the battery fully and take measurements on it through the multimeter.
Maybe it's just time to change it?